Salinity affects millions of hectares of agricultural land in Australia costing hundreds of millions of dollars each year (APH, 2004; Bennett, 2021). It is projected that the area affected by salinity could increase by tens of millions of hectares over time (APH, 2004). Plants and their associated microbiomes, termed holobionts, have evolved to cope with environmental stresses (Trivedi at al., 2020). Under stress conditions plants use mechanisms such as root metabolites, modulated immune defenses, and changes in plant physiology to selectively recruit microbes that confer fitness advantages (Trivedi at al., 2020; Trivedi et al., 2022). Characterising how microbes in the different wheat plant compartments change in richness, abundance and diversity in different environmental conditions is a necessary prerequisite to the development of future technologies such as microbiome engineering. As Australia’s most valuable broadacre crop, wheat is economically important (Australian Bureau of Statistics, 2021). Consequently, it presents a good starting point for characterising the effect of salinity on broadacre crop microbiomes.
Through a greenhouse study, this project aimed to expose wheat plants to three salinity levels (a control, 7dS/m ECe and a treatment of 12dS/m ECe). Each treatment had five replicates and samples were destructively collected from the bulk soil, root rhizosphere, and root endosphere at the tillering stage and shortly before plant maturity. High-throughput sequencing was used to focus on the 16S rRNA region and the ITS region for bacteria and fungi respectively. Data analysis is currently ongoing and will compare the diversity, richness and composition of bacterial and fungal communities within different compartments of the wheat plants when exposed to varying salinity levels. Additionally, plant biomass, was measured and transcriptomics will also be conducted to understand differential gene expression in different salinity conditions. It is hoped that this study will reveal new insights into the response of wheat microbiomes to salinity stress and help inform future studies and potentially technologies to better manage this challenge.